Improvement of the dispersion degree in incompatible polystyrene/poly(n-butylmethacrylate) blends by the graft poly(2,6-dimethyl-1,4-phenylene oxide) on poly(n-butylmethacrylate)

Using optical and electron microscopy it is evidenced that the introduction of graft copolymer poly(2,6-dimethyl-1,4-phenylene oxide) on poly (n-butylmethacrylate) improves substantially the degree of dispersion in the incompatible polymer blend polystyrene/poly (n-butylmethacrylate). The action of the copolymer is attributed-besides the mutual dissolution of the PBMA sequences — to the compatiblity between the PPO-grafts and the PS component of the blend. This is supported by the Tg data which show that the Tg of the PS in the blend is influenced by the present graft copolymer. The observed decrease of the Tg is explained by the concomitant admittance in the PS phase of the PBMA backbone together with the PPO grafts.